Endoscope system for treatment of sinusitis

ABSTRACT

An endoscope includes a substantially rigid shaft having a distal end and a proximal portion, the shaft having a first lumen and a second lumen separate from the first lumen, the second lumen containing one or more objective lenses disposed at the distal end thereof. A housing is mounted on the proximal portion of the shaft, the housing including an eyepiece mount and a light input port. An image fiber bundle is disposed in the second lumen, the image fiber bundle extending proximally from adjacent the one or more objective lenses to the eyepiece mount. An illumination fiber bundle is disposed in the second lumen, the illumination fiber bundle extending proximally from the distal end of the shaft to the light input port.

RELATED APPLICATION DATA

This application is a divisional of U.S. application Ser. No. 12/565,661filed on Sep. 23, 2009, now issued as U.S. Pat. No. 8,888,686. Priorityis claimed pursuant to 35 U.S.C. §§119 and 120. The above-noted PatentApplication is incorporated by reference as if set forth fully herein.

FIELD OF THE INVENTION

The field of the invention generally relates to endoscopes and their usein accessing and visualizing sinus passageways. More particularly, thefield of the invention relates to endoscopes and their use in connectionwith methods for the treatment of sinusitis.

BACKGROUND OF THE INVENTION

Sinusitis is a condition affecting over 35 million Americans, andsimilarly large populations in the rest of the developed world.Sinusitis occurs when one or more of the four paired sinus cavities(i.e., maxillary, ethmoid, frontal, sphenoid) becomes obstructed, orotherwise has compromised drainage, either chronically or episodically.Normally the sinus cavities, each of which are lined by mucosa, producemucous which is then moved by beating cilia from the sinus cavity out tothe nasal cavity and down the throat. The combined sinuses produceapproximately one liter of mucous daily, so the effective transport ofthis mucous is important to sinus health.

Each sinus cavity has a drainage pathway or outflow tract opening intothe nasal passage. This drainage passageway can include an ostium, aswell as a “transition space” in the region of the ostia, such as the“frontal recess,” in the case of the frontal sinus, or an “ethmoidalinfundibulum,” in the case of the maxillary sinus. When the mucosa ofone or more of the ostia or regions near the ostia become inflamed, theegress of mucous is interrupted, setting the stage for an infectionand/or inflammation of the sinus cavity, i.e., sinusitis. Though manyinstances of sinusitis may be treatable with appropriate medicates, insome cases sinusitis persists for months or more, a condition calledchronic sinusitis, and may not respond to medical therapy. Some patientsare also prone to multiple episodes of sinusitis in a given period oftime, a condition called recurrent sinusitis.

Balloon dilation has been applied to treat constricted sinus passagewaysfor the treatment of sinusitis. These balloon dilation devices typicallyinvolve the use of an inflatable balloon located at the distal end of acatheter such as a balloon catheter. Generally, the inflatable balloonis inserted into the constricted sinus passageway in a deflated state.The balloon is then expanded to open or reduce the degree ofconstriction in the sinus passageway being treated to facilitate bettersinus drainage and ventilation. At the same time most, if not all, ofthe functional mucosal tissue lining of the sinuses and their drainagepassageways are preserved.

Exemplary devices and methods particularly suited for the dilation ofanatomic structures associated with the maxillary and anterior ethmoidsinuses are disclosed, for example, in U.S. Pat. No. 7,520,876 and U.S.patent application Ser. No. 12/372,691 which are incorporated byreference as if set forth fully herein. The '691 application describes asystem and method for treating the maxillary ostium and the ethmoidinfundibulum using a balloon dilation catheter placed under directvisualization with a small, flexible endoscope that resides within alumen of the cannula. The cannula includes a second, larger workingchannel that is used for the introduction of the balloon dilationcatheter. In this system, the flexible endoscope extends proximally fromthe cannula and is connected at its proximal end to a camera. This imagecan then be displayed on a monitor or the like. The flexible endoscopesused in connection with embodiments of this type are typically reusableand resterilizable. Unfortunately, these endoscopes are also relativelyfragile and there is a risk of damage occurring during the sterilizationand cleaning process. There thus is a need for a more robust endoscopedesign that can be used in medical procedures such as, for instance, thetreatment of sinusitis.

SUMMARY OF THE INVENTION

In a first embodiment, an endoscope includes a substantially rigid shafthaving a distal end and a proximal portion, the shaft having a firstlumen and a second lumen separate from the first lumen, the second lumencontaining one or more objective lenses disposed at the distal endthereof. A housing is mounted on the proximal portion of the shaft, thehousing including an eyepiece mount and a light input port. An imagefiber bundle is disposed in the second lumen, the image fiber bundleextending proximally from adjacent the one or more objective lenses tothe eyepiece mount. An illumination fiber bundle is disposed in thesecond lumen, the illumination fiber bundle extending proximally fromthe distal end of the shaft to the light input port.

In a second embodiment, a method for treating sinusitis includes formingan artificial passageway into the maxillary sinus with an access sheathassembly comprising a shaft and a handle, the shaft traversing thecanine fossa region of the subject. An endoscope is advanced into theshaft of the access sheath assembly, the endoscope having asubstantially rigid shaft comprising a working lumen and a separateoptics lumen separate from the first lumen, the shaft partially heldwithin a housing including an eyepiece and a light input portoperatively connected to a light source wherein said endoscope isadvanced until the housing abuts the handle. A balloon catheter is thenadvanced along the working lumen of the endoscope so as to place theballoon into the maxillary sinus outflow tract and the balloon isdilated.

In a third embodiment, a system for use in sinus procedures includes anaccess sheath assembly having a shaft containing a lumen therein and ahandle disposed at a proximal end of the shaft. The system furtherincludes an endoscope comprising a substantially rigid shaft having adistal end and a proximal portion, shaft comprising a working lumen andan optics lumen separate from the working lumen, the optics lumenconfigured to hold an illumination fiber bundle and an imaging fiberbundle, the shaft dimensioned for axial movement within the lumen of theaccess sheath. The endoscope further includes a housing mounted on theproximal portion of the shaft and including an eyepiece mountoperatively coupled to the imaging fiber bundle, the housing furthercomprising a light input port operatively coupled to the illuminationfiber bundle. The system also includes a balloon catheter dimensionedfor axial movement within the working lumen of the endoscope shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an endoscope configured formedical procedures such as the treatment of sinusitis.

FIG. 2 illustrates a side view of the endoscope of FIG. 1.

FIG. 3 illustrates a perspective view of an endoscope of FIG. 1 with aballoon catheter disposed in the working lumen or channel of theendoscope.

FIG. 4 illustrates a perspective view of the endoscope with a camerasecured to the eyepiece of the endoscope. A light cable is alsoillustrated as being secured to the light input post.

FIG. 5 illustrates a magnified perspective view of the distal end of thescope shaft of the endoscope.

FIG. 6 illustrates a cross-sectional view of a central portion of theendoscope illustrated in FIG. 1.

FIG. 7 illustrates a cross-sectional view of the eyepiece.

FIG. 8A illustrates a cross-sectional side view of the endoscope shaftand proximal port secured thereto.

FIG. 8B illustrates a cross-sectional view taken along the line A-A′ ofFIG. 8.

FIG. 8C illustrates a cross-sectional view taken along the line B-B′ ofFIG. 8.

FIG. 8D illustrates a cross-sectional view taken along the line C-C′ ofFIG. 8.

FIG. 9A illustrates a magnified, cross-sectional view of the distal endof the endoscope.

FIG. 9B illustrates a cross-sectional view taken along the line A-A′ ofFIG. 9A.

FIG. 10A illustrates a perspective view of an access sheath assemblyhaving a removable extender secured to a proximal end.

FIG. 10B illustrates a perspective view of an access sheath assemblyhaving a removable extender removed from a proximal end.

FIG. 11A illustrates a side view of the access sheath assembly with theoptional extension element.

FIG. 11B illustrates a proximal end view of the access sheath assembly.

FIG. 12A illustrates the trocar and access sheath assembly with thetrocar inserted inside the access sheath assembly.

FIG. 12B illustrates the trocar and access sheath assembly with theaccess sheath assembly separated from the trocar.

FIG. 13 illustrates an endoscope system of the type described hereinused to provide access to the maxillary sinus cavity via the caninefossa route. The access sheath assembly is mounted on the endoscopeshaft and a balloon catheter is illustrated as being advanced into theoutflow tract or ostia of the maxillary sinus cavity.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIGS. 1-3 illustrate an endoscope 2 suitable for sinus proceduresaccording to one aspect of the invention. As seen in FIGS. 1-3, theendoscope 2 includes a shaft 4 that extends distally with respect to ahousing 6. The endoscope 2 further includes an eyepiece mount 8 that isconfigured to secure an eyepiece 10. The eyepiece 10 may include anoptional camera mount 12 that is configured to attach a camera or thelike such that images obtained from the endoscope 2 may be displayed ona monitor (not shown) for real-time viewing. FIG. 4, for example,illustrates a camera 18 that is secured to the camera mount 12. Theendoscope 2 further includes a proximal port 14 that is secured to theproximal end of the shaft 4. The proximal port 14 may also be secured tothe housing 6. The proximal port 14 may, in some embodiments, be formedintegral with the shaft 4 or the housing 6. As explained herein, theproximal port 14 provides access to an interior working lumen 38 of theshaft 4. The endoscope 2 further includes a light input port 16 that maybe operatively coupled to a source of illumination light such as lightcable 28.

Generally, the total length of the endoscope 2 from the proximal port 14to the distal tip of the shaft 4 is generally within the range of about5 inches to about 7 inches. The length of the housing 6 (excludingproximal port 14) is generally within the range of about 1.5 inches toabout 2 inches. The length of the shaft 4 that extends distally from thehousing 6 generally within the range of about 2 inches to about 3inches.

FIG. 3 illustrates an endoscope 2 with a balloon catheter 20 that hasbeen advanced within the endoscope 2. The balloon catheter 20 generallyincludes an elongate member 22 that has an expandable balloon 24disposed at the distal end (shown deflated). The interior of the balloon24 is in fluid communication with an inner lumen (not shown) containedwithin the elongate member 22. The proximal end of the balloon catheter20 includes a hub 26. The hub 26 generally comprises a connector that isconfigured to mate or couple with a syringe (not shown) that contains aninflation fluid. The hub 26 may include, for instance, a Luer connectorknown to those skilled in the art. An example of a balloon catheter 20and syringe that may be used in connection with the endoscope 2 may befound in U.S. application Ser. No. 12/372,691 which is incorporated byreference as if set forth fully herein. Of course, other ballooncatheters 20 and syringes may be used in connection with the endoscope2. Further still, other working devices besides or conjunction with theballoon catheter 20 may be used along with endoscope 2 include cutters,suction catheters, drug delivery catheters, probes, and the like.

Referring now to FIGS. 1-3, and 8A, the shaft 4 is a substantially rigidstructure that generally resists substantial bending movements. Theshaft 4 includes a distal end 30 that may optionally include a partiallybeveled tip 32. The shaft 4 may be formed from multiple segments thatare then secured to one another in a final assembly. For example, asbest seen in FIG. 8A, the shaft 4 includes a distal segment 34 and aproximal segment 36. The distal segment 34 may be formed from a metallicmaterial such as stainless steel or other rigid materials includingmolded plastic. The distal segment 34, as seen in cross-section in FIG.8B, includes a working lumen 38 and an optics lumen 40. The workinglumen 38 and the optics lumen 40 are separated from one another by awall or septum 42. As seen in FIG. 8B, the outer circumference of thedistal segment 34 has an outer profile that is circular or cylindricalin shape. The septum 42 extends longitudinally along the length of thedistal segment 34 and defines the working lumen 38 and the optics lumen40. As best seen in FIG. 8B, both the working lumen 38 and the opticslumen 40 are semi-circular in shape.

In one aspect, the working lumen 38 and the optics lumen 40 are cutusing wire electrical discharge machining (EDM) processing. In thismanner, the shapes of the working lumen 38 and the optics lumen 40 canbe optimized to allow for large lumen cross-sectional areas yet avoidsharp internal corners by having a radius on the corners as best seen inFIG. 8B. While various sizes for the shaft 4 are contemplated, thedistal segment 34 may have an outer diameter that is within the range ofabout 2.5 mm to about 3.5 mm. The working lumen 38 has a range ofdimensions depending on the particular size of the shaft 4. Forinstance, the working lumen 38 may have a width (in the distal segment)of around 0.103 inches and a height of around 0.070 inches. The opticslumen 40 may also have a range of dimensions depending on the particularsize of the shaft 4. An exemplary size of the optics lumen 40 is a widthof around 0.060 inches and a height of around 0.034 inches. The wallthickness of the shaft 4 in the distal segment 34 generally rangesbetween about 0.005 inches and about 0.015 inches. The width of theseptum 42 is typically constant along the length of the shaft 4 andfalls within the range of about 0.003 inches and about 0.005 inches. Ofcourse, alternative dimensions are contemplated, the dimensions of whichwill depend on the size of the working device passing through theworking lumen 38, the size of the optical components, and the desiredstiffness qualities of the shaft 4.

Now referring to FIG. 8C, the proximal segment 36 of the shaft 4 onlyhas a single lumen which is the working lumen 38. The proximal segment36 has an outer profile that is semi-circular in shape as best seen inFIG. 8C. The dimensions of the working lumen 38 in the proximal segment36 may generally be the same as those in the distal segment 34. Theproximal segment 36 may also be formed from a metal such as stainlesssteel. The proximal segment 36 may have the working lumen 38 formed bywire EDM processing from a solid rod. As best seen in FIGS. 8A and 8D,the proximal segment 36 changes from the semi-circular shape as seen inFIG. 8C toward a more circular shape as one moves in the proximaldirection as seen in FIG. 8D. This transition facilitates the passage ofa working device such as a balloon catheter 20 from the proximal port 14into the smaller working lumen 38 of the distal segment 34. The proximalsegment 36 of the shaft 4 may be connected to the distal segment 34 ofthe shaft 4 via a joint 44. The joint may include, for example, alaser-welded butt joint or the like.

As best seen in FIGS. 5, 8A, and 9A, the distal end 30 of the shaft 4terminates in a partially beveled tip 32. In this embodiment, thebeveled tip 32 covers the working lumen 38 while the optics lumen 40terminates in a face that is generally perpendicular to the longitudinalaxis of the shaft 4. The beveled tip 32 along with the rounding of thedistal edges of the shaft 4 facilitate the withdrawal of a deflatedballoon catheter 20 following dilation of the balloon 24. Without thebeveled tip 32 there is a risk that the “wings” of the deflated balloon24 can “hang up” on the distal edge of the shaft 4, risking damage ortearing of the balloon 24. The optics lumen 40 is used to carryilluminating light via an illumination fiber bundle 50 from the lightinput port 16 to the distal end 30 via an image fiber bundle 80 as wellas carry reflected light (i.e., an optical image) back to the eyepiecemount 8 and into eyepiece 10. For light illumination, an illuminationfiber bundle 50 is disposed in the periphery of the optics lumen 40.More specifically, the various fibers forming the illumination fiberbundle 50 populate the portion of the optics lumen 40 that is externalto an objective sleeve 52 that holds various other optical components asexplained in more detail below.

The illumination fiber bundle 50 consists of a plurality of randomlyspaced individual fiber optic filaments that terminate at the distal end30 of the shaft 4 and extend proximally through the optics lumen 40 andexit the optics lumen 40 where they pass through the interior of thehousing 6 with a terminus at the light input port 16. The specificquantity of optic filaments (e.g., glass strands) should generally besufficient to substantially illuminate the target area around at least0.78 mm². Each fiber of the illumination fiber bundle 50 generallyconsists of individual glass strands in the range of 30 μm to 50 μm indiameter containing a core and a cladding that have different refractiveindices. Typical illumination fibers have a light refracting index inthe range of 0.5 to 0.86 numerical aperture (NA). The light fiberbundles may be obtained commercially from, for example, Schott NorthAmerica, Inc. (Southbridge, Mass.) although other sources maybe used.The light input port 16 preferably includes a fiber optic light taper 54that is used to help collect and intensify the light that is deliveredto the illumination fiber bundle 50. The taper 54 enables many fibers tocollect light over a larger area thereby concentrating the light to thediameter of the illumination fiber bundle 50. The degree of taper (e.g.,ratio of input diameter to output diameter in taper 54) in fiber opticlight taper 54 depends but generally should be around 3:1. As best seenin FIG. 6, the light input port 16 is mounted at an angle relative tothe long axis of the shaft 4 to thereby provide better access to theproximal port 14.

Referring to FIGS. 6 and 8A, the proximal port 14 is connected theproximal segment 36 of the shaft 4. The proximal port 14 may be made ofa metallic material such as stainless steel and can be welded directlyto the proximal segment 36 of the shaft 4. The proximal port 14 alsoextends proximally from a proximal end of the housing 6 and alsoincludes a funnel portion 56 to allow easy guidance and passage of aworking device into the working lumen 38. The proximal end of theproximal port 14 may be configured to mate with a male Luer fitting orthe like as is known in the art.

The housing 6, which encapsulates a portion of the shaft 4, is also madefrom a material that is capable of withstanding sterilization processes.For example, the housing 6 may be made from stainless steel or the like.As best seen in FIGS. 1-3, the distal end 60 of the housing 6 terminatesat a projection or stop 62 that, as explained below, engages with thehandle 112 of an access sheath assembly 110 to limit distal advancement.The stop 62 may also include a sleeve interface 64 that is configured toremovably hold a protective sleeve or cover (not shown) that is affixedto the endoscope 2 during the sterilization process either before orafter the use of the endoscope 2 in a surgical procedure.

Referring now to FIGS. 5 and 9A, the components related to transferringback the optical image are discussed. The distal end of the optics lumen40 includes a protective window 70 that is contained within theobjective sleeve 52. The protective window 70 is made from an opticallytransparent material such as glass or the like and has a flat distalsurface that facilitates mechanical cleaning of any accumulated materialsuch as blood or mucous that occasionally gets deposited on theendoscope 2. Located just proximal to the window 70 is an aperture 72that includes an opening that is dimensioned to limit the angle at whichreflected light can enter the downstream optics described below. Theaperture 72 minimizes internal light interference as well as increasesthe depth of field of the image. However, if the opening in the aperture72 is too small, the overall image will also tend to be too dark. Theaperture 72 may range in size but generally falls within the range ofabout 0.25 mm to about 0.75 mm in outer diameter with an inner diameteropening approximately 0.10 to 0.5 mm in diameter and a thickness of 25μm to 125 μm which can all be varied depending on the optical qualitiesdesired.

Still referring to FIG. 9A, located proximally with respect to theaperture 72 are a plurality of objective lenses 74, 76. The objectinglenses 74, 76 may consist of two glass lenses with abutting convexsurfaces which serve to focus the image proximally onto the distal faceof a coherent image fiber bundle 80. The objective focal length for bothlenses 74, 76 is between 5 to 10 mm. A small adjustable gap 82 locatedbetween the proximal-most objective lens 76 and the distal end of theimaging fiber bundle 80 can be “dialed in” during manufacture of theendoscope 2 to adjust the focal distance of the endoscope 2. In oneaspect, the window 70, aperture 72, and objective lenses 74, 76 are allmounted within the objective sleeve 52 using suitable means such asadhesive, resulting in the formation of an objective assembly 84. Theobjective assembly 84 is then secured within the optics lumen 40, alsoby suitable means such as adhesive.

As seen in FIGS. 5 and 9B, the objective assembly 84 is located in thecentral portion of the semi-circular optics lumen 40 while theillumination fiber bundle 50 is spread out and disposed along therounded corners of the semi-circular optics lumen 40. The image fiberbundle 80 extends proximally through the optics lumen 40 eventuallyextending out of the optics lumen 40 at the joint 44 where the imagefiber bundle 80 continues until it ends at terminus 81 located in theeyepiece mount 8. The image fiber bundle 80 is preferably a fused imagebundle as is known in the art. The image fiber bundle 80 preferablyincludes from about 3,000 to about 50,000 individual fused opticalfilaments, and more preferably about 10,000 to about 30,000 opticalfilaments. Depending on the space available for the image fiber bundle80, some bundles can be fabricated in a “ultra-thin” configuration whereeach individual fiber in the bundle is reduced in size resulting in anoverall smaller bundle diameter but still achieving a high number ofoptical filaments. Such an image fiber bundle 80 is availablecommercially from Fujikura (Japan) although such image fiber bundles 80may be obtained from alternative sources. The image fiber bundle 80generally has an overall diameter in the range of 0.28 mm to 1.2 mm andterminates at the proximal end 9 of the eyepiece mount 8. The imagefiber bundle 80 preferably curves as is shown in FIG. 6 to facility theangularly offset eyepiece mount 8.

FIGS. 6-7 illustrate further details of the eyepiece 10 which isconnected to the eyepiece mount 8. The eyepiece 10 includes a bodyportion 88 that includes two o-ring seals 90, 92 located at opposingends. The distal o-ring 90 is used to seal the eyepiece body portion 88to the eyepiece mount 8. The proximal o-ring 92 is used for sealingengagement with an eyepiece cup 94. A series of magnifying lenses 96,98, 100 are located along the length of the body portion 88 and are usedto magnify the image. A series of lens spacers 102, 104, 106 separatemagnifying lenses 96, 98, 100 in order that a camera 18 or a human eyecan view the magnified image at the eyepiece cup 94. The eyepiece cup 94may be sized to serve as a camera mount 12 which can be used to secure acamera 18 (as seen in FIG. 4) that can be used to display the endoscopicimage on a monitor or screen so the physician can obtain real-timeimages of the field of view out the distal end 30 of the endoscope 2.The field of view out the distal end 30 of the endoscope 2 is around 70degrees. In order to facilitate the connection of conventional surgicalcameras, the eyepiece 94 includes a camera mount 12 such as a “Type B”camera mount that is standard and fits most cameras.

The working lumen 38 has been primarily described herein as beingconfigured to accommodate a balloon catheter 20 that can be used fordilating a sinus drainage passageway. It is contemplated, however, thatvarious other devices may be passed through the working lumen 38including suction devices, aspiration devices, cutting instruments,infusion devices, devices that deliver or administer pharmacologicagents, or the like.

As best seen in FIGS. 10A, 10B, 11A, 11B, 12A, 12B and 13, the endoscope2 described herein is used in connection with an access sheath assembly110. The access sheath assembly 110 generally includes a handle 112 thatincludes a distal end 114 and a proximal end 116. The periphery of thehandle 112 may be ergonomically designed to assist gripping by thephysician. For example, the handle 112 may include a gripping surface118 that may include a contours or the like. The proximal end 116 of thehandle 112 includes a slot 120 that is dimensioned to receive anoptional extension element 122. The extension element 122 comprises asemi-tubular length of material that is open on one side and effectivelyextends the length of the handle 112.

The extension element 122 may be made of metal such as stainless steeland thus reusable. Alternatively, the extension element 122 may be adisposable in which case, it could be made from non-sterilizablematerials such as plastic or the like. The extension element 122includes a rim 124 located at a distal end thereof that is configured toengage with the slot 120 of the handle 112. In this regard, theextension element 122 can be “locked” to the proximal end 116 of thehandle 112 when desired. The extension element 122 can be removed fromthe handle 112 by laterally sliding the rim 124 from the slot 120. Inmost cases, the extension element 122 is left connected to the handle112. In other cases, however, such as treating a large maxillary sinus,the extension element 122 can be removed.

As seen in FIG. 11B, the proximal end 116 of the handle 112 includes anopening 117 that provides access to the lumen 126 of a shaft 128 that isconnected to the handle 112 and extends distally there from. The lumen126 is dimensioned to receive the shaft 4 of the endoscope 2 asexplained herein. The shaft 128 may have a beveled tip 130 along with alongitudinal cutting surface 132 formed on the exterior surface of theshaft 128. The cutting surface 132 may be formed from a plurality ofcutting flutes 134 that are longitudinally oriented on the shaft 128. Anengagement ridge 136 is provided near the beveled tip 130. Engagementridge 136 serves to maintain the position of the shaft 128 within theaccess hole within the sinus, to prevent inadvertent withdrawal of theaccess sheath 110 from the patient.

The shaft 128 is rigid and typically made of a metallic material such asstainless steel. The cutting surface 132 facilitates the entry into thesinus cavity when mounted on a trocar 140 as illustrated in FIG. 12Awhich is used to penetrate the canine fossa region 142 of the subjectand provide an artificial access passageway 144 into the maxillarysinus. The access sheath assembly 110 may be re-oriented or re-angledusing the cutting surface 132 to better orient the access sheathassembly 110 to point toward the sinus outflow tract of interest. Theshaft 128 may include a tissue stop 138 in the form an enlarged diameterflanged portion that limits the depth of penetration of the accesssheath assembly 110 into the maxillary sinus. Additional access sheathassemblies 110 suitable for use with the endoscope 2 may be found inU.S. patent application Ser. No. 12/038,719, which is incorporated byreference as if set forth fully herein.

When used in a sinus procedure, an artificial access passageway is firstformed in the canine fossa region 142 of the patient. This isaccomplished by placing a trocar 140 within the lumen 126 of the accesssheath assembly 110. The trocar 140 and access sheath assembly 110 areadvanced together distally while simultaneously rotating the shaftportion 128 and the trocar 140 back and forth. This may be accomplishedvia the handle 112. The beveled tip 130 is essentially drilling throughbone to gain access to the maxillary sinus cavity. The sinus mucosa istypically soft, and does not require further drilling to penetrate, butrather will yield upon longitudinal advancement of the trocar 140 andaccess sheath assembly 110. In this example, the trocar 140 and accesssheath 110 enter the maxillary sinus through or near the canine fossaregion 142. An artificial passageway 144 is thus formed in the caninefossa region 142. However, it is contemplated that the sinus could beaccessed in other areas. Also, other sinuses, e.g. the frontal sinus,could be accessed using the access sheath assembly 110 and trocar 110.

Access to the maxillary sinus may be obtained while maintaining thetrocar 140 and access sheath assembly 110 on a consistent path or anglerelative to the subject. That is to say, the trocar 140 and accesssheath assembly 110 are inserted through the bone in a straightdirection along the longitudinal axis of the access sheath assembly 110.The resultant artificial passageway 144 in the bone is therefore shapedin a relatively cylindrical fashion through the wall thickness of thebone. The access sheath assembly 110 and the trocar 140 may be advancedinto the canine fossa 142 using a first orientation of the access sheathassembly 110 and trocar 140 so as to avoid penetrating sensitive tissueor structures with the beveled tip 130 of the access sheath assembly110. Next, the access sheath assembly 110 may be re-oriented once accesshas been made. This may be accomplished by rotating the access sheathassembly 110 and trocar 140 while simultaneously panning the accesssheath assembly 110 to change the access sheath assembly 110 into asecond orientation. The panning motion may include moving the accesssheath assembly 110 in a direction substantially orthogonal to thelongitudinal axis of the access sheath assembly 110. In this secondorientation, the longitudinal axis of the access sheath assembly 110 istilted toward the maxillary ostium to provide a more “direct shot”toward this area.

The rotation of the access sheath assembly 110 causes the cuttingsurface 132 to “ream” or “side-cut” some of the bone defining theoriginal artificial passageway 144. In addition, re-angling or panningthe access sheath assembly 110 at the same time the access sheathassembly 110 is rotated causes additional reaming to take place. In oneaspect of the invention, once the access sheath assembly 110 is at adesired angle, the trocar 140 can be removed, leaving the access sheathassembly 110 in the sinus cavity. Additional details regarding theprocess of inserting the access sheath assembly 110 into the caninefossa region 142 may be found in U.S. application Ser. No. 12/038,719.

Now referring to FIG. 13, once the access sheath assembly 110 ispositioned as desired and the trocar 140 is removed, the endoscope 2 isthen advanced into the lumen 126 of the shaft 128. This is accomplishedby advancing the shaft 4 of the endoscope 2 through the proximal openingof the extension element 122 (if used) and into the lumen 126 of theshaft 128. The endoscope 2 is advanced distally until the stop 62located at the distal end 60 of the housing 6 abuts the extensionelement 122 as illustrated in FIG. 13. Alternatively, if the extensionelement 122 is not used, the stop 62 will abut the proximal end 116 ofthe housing 112. Because the endoscope 2 abuts either the extensionelement 122 or the housing 112 continued forward stabilizing force inthe direction of the sinus cavity will maintain the endoscope 2 at adesired distance away from the area of interest, which in the case ofFIG. 13, is the maxillary sinus outflow tract. Only one of theoperators' respective hands is needed for this positioning process andthe maintenance of that position during the remaining steps of theprocedure described below, as force applied to the endoscope 2 in thedirection of the artificial passageway 144 will keep the access sheathassembly 110 in position.

Once the endoscope 2 is properly positioned within the access sheathassembly 110, the outflow tract (e.g., maxillary sinus outflow tract) isthen viewed via the endoscope 2. The eyepiece 10 may be viewed directlyby the operator or, alternatively, a camera 18 may be used to display amagnified version of the field of view on a display or monitor (notshown). In this regard, the operator obtains a real-time image of theoutflow tract.

A working device such as a balloon catheter 20 is then advanced alongthe working lumen 38 of the endoscope 2. This is accomplished by feedingthe balloon catheter 20 with the balloon 24 in a deflated state into theproximal port 14 and advancing the balloon catheter 20 in the distaldirection. The balloon catheter 20 is advanced until the distal tip ofthe catheter and balloon 24 are then placed in or across the outflowtract. While one hand of the operator holds the endoscope 2, the otherhand of the operator is used to maneuver the balloon catheter 20 intoposition. This advantageously results in a user-friendly, two-handedprocedure. The balloon catheter 20 includes a proximal hub 26 that iscoupled in an inflation device such as a syringe (not shown). Anexemplary syringe that can be used to inflate the balloon 24 isillustrated in U.S. patent application Ser. No. 12/372,691 althoughother syringes may also be used.

Once the outflow tract is adequately dilated through inflation of theballoon 24, the balloon 24 is deflated and the balloon catheter 20 isthen proximally retracted from the endoscope 2. The endoscope 2 may thenbe removed from the access sheath assembly 110. Finally, the accesssheath assembly 110 may be withdrawn from the artificial passageway 144.Of course, the specific order of the removal of the various componentsmay vary. For instance, both the balloon catheter 20 and the endoscope 2may be removed from the access sheath assembly 110 at substantially thesame time. In addition, the access sheath assembly 110 may also bewithdrawn from the artificial passageway 144 at substantially the sametime as a working device (e.g., balloon catheter 20) contained in thelumen 126.

While embodiments of the present invention have been shown anddescribed, various modifications may be made without departing from thescope of the present invention. The invention, therefore, should not belimited, except to the following claims, and their equivalents.

What is claimed is:
 1. An endoscope comprising: a substantially rigidshaft having a distal end and a proximal portion, the shaft comprising afirst lumen and a second lumen separated from the first lumen via aseptum, the second lumen containing one or more objective lensesdisposed at the distal end thereof, wherein the distal end includes adistal tip having a face portion that is substantially perpendicular toa long axis of the shaft and contains a distal end of the second lumen,and a beveled portion connected at a distal-most point to the faceportion and extending proximally at an angle to the long axis of theshaft from the face portion to an outer surface of the shaft wherein thebeveled portion contains a distal end of the first lumen, and whereinthe distal end of the first lumen and the distal end of the second lumenare parallel and substantially aligned along the long axis of the shaft;a housing mounted on the proximal portion of the shaft, the housingincluding an eyepiece mount and a light input port; an image fiberbundle disposed in the second lumen, the image fiber bundle extendingproximally from adjacent the one or more objective lenses to theeyepiece mount; an illumination fiber bundle disposed in the secondlumen, the illumination fiber bundle extending proximally from thedistal end of the shaft to the light input port; a balloon dilationcatheter disposed in the first lumen of the shaft, wherein the firstlumen is dimensioned to accommodate axial advancement and retraction ofthe balloon dilation catheter there through; an access sheath assemblycomprising a handle having a proximal end containing a slot and a shaftextending from the handle, the shaft terminating in a beveled tip andhaving a lumen extending there through and dimensioned to accommodatethe substantially rigid shaft of the endoscope; and an extension elementcomprising a rim at a distal end thereof, the extension elementremovably secured to the handle by securing the rim to the slot of thehandle.
 2. The endoscope of claim 1, wherein the shaft of the accesssheath assembly comprises a cutting surface disposed about theperiphery.
 3. The endoscope of claim 1, the housing comprising a stoplocated at a distal end thereof, the stop configured to engage with thehandle of the access sheath assembly.
 4. The endoscope of claim 1,wherein the eyepiece mount is angled relative to the longitudinal axisof the substantially rigid shaft.
 5. The endoscope of claim 1, whereinthe light input port comprises a tapered portion.
 6. The endoscope ofclaim 1, wherein the light input port is angled relative to thelongitudinal axis of the substantially rigid shaft.
 7. The endoscope ofclaim 1, further comprising an optically transparent window disposed inthe second lumen and distally with respect to the one or more objectivelenses.
 8. The endoscope of claim 7, further comprising an apertureinterposed between the optically transparent window and the one or moreobjective lenses.
 9. The endoscope of claim 1, further comprising aproximal port secured to the proximal portion of the substantially rigidshaft.
 10. The endoscope of claim 1, wherein the shaft comprises adistal portion containing the first and second lumens and a proximalportion containing only the first lumen, the distal and proximal shaftportions being secured to one another at a joint.